From: Glauber de O. C. <gc...@re...> - 2008-01-11 13:11:02
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Hi folks, A lot of time has been elapsed since I last sent a version of kvm clock, with a lot of things in the middle, including my vacations and a nasty bug in the clock itself ;-) Here it is a new version. I'm following avi's last suggestion of using an msr to make it more migration-proof. If it's not approved, we can easily switch back to the hypercall mechanism. That's the easy part ;-) Clock updates are done every time we're scheduled. It is _not_ enough to check if we're changing cpus, because the tsc will change its frequency when the cpu is idle (if using the mwait idle). So after a long idle period, one cpu will end up stepping ahead causing a backward time (remember the bug I talked about? :-) ) As I fell it ready for inclusion (which obviously does not mean it is perfect, nor that I don't value any further comments ), I'm also posting the userspace patches in a separate series that will follow shortly. |